This invention relates to a method and an apparatus for feedback control of the ignition timing of internal combustion engines in order to increase the output of the engines and improve the fuel consumption rate.
The ignition timing of an internal combustion engine has been controlled by the engine speed and the intake pressure, etc. depending on a driving state of the engine, to maximize the output of the engine and at the same time minimize the fuel consumption rate, so long as there are no speical problems such as knocking or exhaust gas emission, etc. arising. However, due to variations of each engine and variations in environmental conditions it has been difficult to control timing accurately. Hence, a certain decrease in output and an increase in fuel consumption rate have been unavoidable.
As another method for increasing the output of the engine and reducing the fuel consumption rate, ignition timing has been feedback controlled. A base value of the ignition timing of the engine is recorded in a memory and the record content is rewritten depending on the occurrence of knocking, etc. However, in this method, the record content of the memory is rewritten only by a signal indicating the driving state such as the occurrence of knocking, etc. It has been difficult to control accurately the ignition timing to the standard value.